Anatomical characteristics and wood properties of unutilized Artocarpus species found in secondary forests regenerated after shifting cultivation in Central Kalimantan, Indonesia

The anatomical characteristics and wood properties of Artocarpus species naturally regenerated in secondary forests in Central Kalimantan, Indonesia, were investigated to determine their usefulness as alternative wood resources. The following six Artocarpus species were used in the present study: A. dadah, A. nitidus, A. elasticus, A. tamaran, A. anisophyllus, and A. odoratissimus. The mean value of stress-wave velocity was 3.22 km s−1 for 12 trees from the six Artocarpus species. Among the six species, A. dadah, A. nitidus, and A. odoratissimus showed relatively higher stress-wave velocity values compared to those of other tropical commercial plantation species, indicating that the woods in these three Artocarpus species have higher values of Young’s modulus. The mean values for the anatomical and other wood properties of the 12 trees of the six Artocarpus species were as follows: vessel diameter, 150 µm; vessel element length, 0.41 mm; fiber diameter, 19.8 µm; fiber wall thickness, 1.28 µm; fiber length, 1.34 mm; basic density, 0.50 g cm−3; compressive strength parallel to grain at green condition, 31.2 MPa. Basic density was positively correlated with compressive strength, suggesting that the mechanical properties of Artocarpus species can be predicted by measuring the basic density. Based on the results, the six Artocarpus species used in the present study could produce solid lumber for construction, furniture, and other uses, suggesting that these species might be alternative tree species for lumber production in agroforestry in Asian countries.